Slow Vi using analog I/O

Question

Hello,
I'm having issues fixing my labview code to have an efficient response time. I tried multiple things to fix my issue, but can't seem to find a solution. I'm not as comfortable with LabVIEW as I am with other coding languages so troubleshooting this problem has been tough for me.
The purpose of this code is to take in an analog input of a limit switch being pressed, and upon doing so, switching the control from one channel to the other channel. The code works the way I want it to, but the issue is that it's just too slow for the application. Any assistance with this code would be much appreciated.
Attachments:
FES Switch Lab(04_12_12).vi ‏253 KB

Answer 1

Justin,
1. and 2. Most of the 3 seconds comes from the signals you are feeding to the DAQ Assistants. The 2000 constants in the image are the sampling parameters: 2000 samples per second and 2000 samples. That means you have a 1 second signal. You do this twice with different amplitudes and formulas.  To get to less than 200 ms with this program structure you need to change the sampling rate or the number of samples.
3. The code in the case structure is identical in both cases except for a Stop Task (which probably is not needed at all) and the boolean output.  Move the DAQ stuff outside the case structure and only have one copy. The code in the two frames of the sequence structures is the same except for the formula and amplitude. Create arrays of the formula strings and amplitude values and put just one copy of the code in a for loop. You can use the error wires to create data dependencies to make things happen in the desired order.
4. and 5. Anything which is duplicated probably only needs to be there once. If ELVIS retains the values put on the outputs, you would only need to write one sample for each value at the time you want it to change. Your code writes 2000 identical samples and then 2000 more of a different value.
6. How does a constant power supply generate a trigger if it never changes?
I presume the DAQ Assistant2 reads the limit switch.  However, nothing in your code behaves differently as a result of the inputs except the boolean indicators.  If the DAQ writes are supposed to change the channel, you need to write something different for false and true.
Is there a reason for using buttons for indicators? This tends to confuse users who wonder why pushing the buttons does not do anythimg.
Here is a cleaned up version which should work the same as yours.  I do not have any DAQ hardware or the DAQ Assistant so I did not test.
Lynn
Attachments:
FES Switch Lab(04_12_12).2.vi ‏108 KB